1193 PRAME is secreted as a melanoma extracellular vesicle-associated protein

PRAME (PReferentially expressed Antigen in MElanoma) is a protein highly melanoma cells and has long been thought to be nuclear protein; however, our data suggests secreted by via extracellular vesicles (EVs). Using three human cell lines vitro, we found not only detectable the intracellular location (nuclear cytoplasmic fractions), it also EVs Western blot. We used differential centrifugation precipitation methods isolate EVs. nanosight tracking analysis confirm different size of EVs, which likely correspond oncosomes, apoptotic bodies, microvesicles (ectosomes) exosomes, express CD63 CD81. CD63-antibody-conjugated Dynabeads pull-down detect expression. As benign recipient cells, normal melanocytes fibroblasts. associated with inhibition retinoic acid signaling cells. demonstrated that containing were able transfer fibroblasts vitro. This may affect both proliferation relevant vivo. Our study provides evidence utilize active neighbor this influence develop malignant tumor-supporting phenotypes. will impact understanding pathogenesis, major implications for biomarker therapeutic developments advanced patients.